A multi-channel satellite navigation signal source redundancy method suitable for launch vehicles

Abstract

The present invention discloses a multi-channel satellite navigation information source redundancy method applicable to a launch vehicle, wherein a multi-channel satellite navigation receiver sends PPS pulses and positioning information frames containing three navigation information sources of GPS / GLONASS, BeiDou-2 B1 and BeiDou-2 B3 to an onboard computer at a fixed period. The positioning information frame contains the flag bit of each navigation information source, the PDOP value and the position and velocity results under the WGS84 ground fixed system, and performs redundant navigation analysis on the GPS / GLONASS, BeiDou-2 B1 and BeiDou-2 B3 navigation information sources to achieve high-precision and high-reliability redundant navigation.

Description

Technical Field

[0001] The invention relates to a multi-channel satellite navigation information source redundancy method suitable for a carrier rocket, belonging to the technical field of carrier rocket navigation and guidance. Background Art

[0002] During the flight of the launch vehicle, the onboard inertial navigation system and the satellite are combined to position and determine the speed. The tool error of the inertial navigation system itself accumulates over time, causing the speed and position deviation of the launch vehicle to gradually increase during flight. The error can be corrected in real time through combined navigation combined with the parameters of the satellite to ensure that the rocket enters orbit accurately. Improving the reliability of the satellite navigation system can reduce the accuracy requirements for inertial navigation devices, reduce the cost of inertial navigation system development, and simplify the ground equipment system. Therefore, the demand for highly reliable satellite navigation redundancy methods is more urgent. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, and to propose a multi-channel satellite navigation source redundancy method suitable for launch vehicles, to perform redundant navigation analysis based on GPS / GLONASS, BeiDou-2 B1, and BeiDou-2 B3 navigation information sources, and to achieve high-precision and high-reliability redundant navigation.

[0004] The technical solution of the present invention is:

[0005] A multi-channel satellite navigation information source redundancy method applicable to a launch vehicle, comprising:

[0006] The following operations are performed in each cycle when the multi-channel satellite navigation receiver sends the navigation positioning results:

[0007] Step 1: According to the navigation positioning result sent by the multi-channel satellite navigation receiver, the flag information of the GPS / GLONASS navigation information source, the BeiDou-2 B1 navigation information source, and the BeiDou-2 B3 navigation information source is obtained, and the GPS / GLONASS navigation information source, the BeiDou-2 B1 navigation information source, and the BeiDou-2 B3 navigation information source are judged in turn whether they are working normally; if the GPS / GLONASS navigation information source is working normally, go to step 2; if the GPS / GLONASS navigation information source cannot work normally and the BeiDou-2 B1 navigation information source is working normally, go to step 3; if only the BeiDou-2 B3 navigation information source can work normally, go to step 4; if all the above three navigation information sources cannot work normally, go to step 2;

[0008] Step 2: Determine whether the navigation data of the GPS / GLONASS navigation information source is valid. If valid, the fault count of the navigation information source is cleared, the flag is set to normal, and the process goes to step 5. If invalid, the fault count of the navigation information source is increased by 1, and then determine whether the fault count of the navigation information source is less than the preset fault threshold value. If it is less than the preset fault threshold value, the combined navigation is not performed in the current cycle, and the next cycle is waited. Otherwise, the flag is set to fault, and the process goes to step 3.

[0009] Step 3: Determine whether the navigation data of the BeiDou-2 B1 navigation information source is valid. If valid, the fault count of the navigation information source is cleared, the flag is set to normal, and the process goes to step 5; if invalid, the fault count of the navigation information source is increased by 1, and then determine whether the fault count of the navigation information source is less than the preset fault threshold value. If it is less than the preset fault threshold value, the combined navigation is not performed in the current cycle, and the next cycle is waited; otherwise, the flag is set to fault, and the process goes to step 4;

[0010] Step 4: Determine whether the navigation data of the BeiDou-2 B3 navigation information source is valid. If valid, the fault count of the navigation information source is cleared, the flag is set to normal, and the process goes to step 5; if invalid, the fault count of the navigation information source is increased by 1, and then determine whether the fault count of the navigation information source is less than the preset fault threshold value. If it is less than the preset fault threshold value, the combined navigation is not performed in the current cycle, and the next cycle is waited; otherwise, the flag is set to fault, and the combined navigation is not performed in the current cycle, and the next cycle is waited;

[0011] Step 5: Combine the navigation information from the navigation information source with the strapdown inertial navigation system information to perform combined navigation.

[0012] Preferably, the flag information of the GPS / GLONASS navigation information source, the BeiDou-2 B1 navigation information source, and the BeiDou-2 B3 navigation information source is obtained, and it is determined in turn whether the GPS / GLONASS navigation information source, the BeiDou-2 B1 navigation information source, and the BeiDou-2 B3 navigation information source are working normally, specifically:

[0013] If the flag of the GPS / GLONASS navigation information source is normal, it is considered that the navigation information source is working normally; if it is faulty, it is considered that the navigation information source is not working properly;

[0014] If the flag bit of the BeiDou-2 B1 navigation information source is normal, it is considered that the navigation information source is working normally; if it is faulty, it is considered that the navigation information source is not working properly;

[0015] If the flag bit of the BeiDou-2 B3 navigation information source is normal, it is considered that the navigation information source is working normally; if it is faulty, it is considered that the navigation information source is working abnormally.

[0016] Preferably, the determination methods for determining whether the navigation data of the GPS / GLONASS navigation information source is valid, determining whether the navigation data of the BeiDou-2 B1 navigation information source is valid, and determining whether the navigation data of the BeiDou-2 B3 navigation information source is valid are:

[0017] (1) Whether the output flag of the navigation information source to be judged is normal;

[0018] (2) Whether the PDOP value of the navigation information source to be determined is less than a preset PDOP threshold value;

[0019] (3) Whether the speed and position of the navigation information source to be determined are normal;

[0020] If (1) to (3) are all normal, the navigation data of the navigation information source to be determined is valid; otherwise, the navigation data of the navigation information source to be determined is invalid.

[0021] Preferably, whether the speed and position of the navigation information source to be judged are normal, if the navigation information source to be judged is a GPS / GLONASS navigation information source, the judgment method is:

[0022] (31) Determine whether the output flag of the BeiDou-2 B1 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V GNSS -V B1 |≤ε V 、|P GNSS -P B1 |≤ε P ; If both of the above two formulas are satisfied, the speed and position of the GPS / GLONASS navigation information source are considered normal; otherwise, go to (32);

[0023] Where V B1 , P B1 is the velocity and position of BeiDou-2B1 in the launch inertial system, V GNSS , P GNSS is the velocity and position of GPS / GLONASS in the transmitting inertial system, ε V , ε P It is the preset speed threshold value and position threshold value;

[0024] (32) Determine whether the output flag of the BeiDou-2 B3 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V GNSS -V B3 |≤ε V 、|P GNSS -P B3 |≤ε P; If both of the above two formulas are satisfied, the speed and position of the GPS / GLONASS navigation information source are considered normal; otherwise, go to (33);

[0025] Where V B3 , P B3 is the speed and position of BeiDou-2B3 in the launch inertial system;

[0026] (33) Determine whether |dV is satisfied GNSS -dV SINS |≤ε dV 、|dP GNSS -dP SINS |≤ε dP If the conditions are met, the speed and position of the GPS / GLONASS navigation information source are considered normal; otherwise, the speed and position of the GPS / GLONASS navigation information source are considered abnormal.

[0027] Where, dV SINS 、dP SINS is the velocity increment and position increment of the strapdown inertial unit in the launch inertial system, dV GNSS 、dP GNSS is the velocity increment and position increment of the strapdown inertial group in the launching inertial system, ε dV , ε dV It is the preset speed increment threshold and position increment threshold.

[0028] Preferably, whether the speed and position of the navigation information source to be judged are normal, if the navigation information source to be judged is the BeiDou-2 B1 navigation information source, the judgment method is:

[0029] (41) Determine whether the output flag of the GPS / GLONASS navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B1 -V GNSS |≤ε V 、|P B1 -P GNSS |≤ε P ; If both of the above two formulas are satisfied, it is determined that the speed and position of the BeiDou-2 B1 navigation information source are normal; otherwise, enter (42);

[0030] Where V B1 , P B1 is the velocity and position of BeiDou-2B1 in the launch inertial system, V GNSS , P GNSS is the velocity and position of GPS / GLONASS in the transmitting inertial system, ε V , ε P It is the preset speed threshold value and position threshold value;

[0031] (42) Determine whether the output flag of the BeiDou-2 B3 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B1 -V B3 |≤ε V 、|P B1 -P B3 |≤ε P ; If both of the above two formulas are satisfied, it is determined that the speed and position of the BeiDou-2 B1 navigation information source are normal; otherwise, enter (43);

[0032] Where V B3 , P B3 is the speed and position of BeiDou-2B3 in the launch inertial system;

[0033] (43) Determine whether |dV is satisfied B1 -dV SINS |≤ε dV 、|dP B1 -dP SINS |≤ε dP If the conditions are met, the speed and position of the BeiDou-2 B1 navigation information source are considered normal; otherwise, the speed and position of the BeiDou-2 B1 navigation information source are considered abnormal.

[0034] Where, dV B1 、dP B1 is the velocity increment and position increment of BeiDou-2B1 in the launch inertial system, dV SINS 、dP SINS is the velocity increment and position increment of the strapdown inertial group in the launching inertial system, ε dV , ε dV It is the preset speed increment threshold and position increment threshold.

[0035] Preferably, whether the speed and position of the navigation information source to be judged are normal, if the navigation information source to be judged is the Beidou-2 B3 navigation information source, the judgment method is:

[0036] (51) Determine whether the output flag of the GPS / GLONASS navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B3 -V GNS|S ≤ε,|P B3 -P GNSS |≤ε P ; If the above two formulas are satisfied, the speed and position of the BeiDou-2 B3 navigation information source are considered normal; otherwise, go to (52);

[0037] Where VB3 , P B3 is the velocity and position of BeiDou-2B3 in the launch inertial system; V GNSS , P GNSS is the velocity and position of GPS / GLONASS in the transmitting inertial system, ε V , ε P It is the preset speed threshold value and position threshold value;

[0038] (52) Determine whether the output flag of the BeiDou-2 B1 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B3 -V B1 |≤ε V 、|P B3 -P B1 |≤ε P ; If the above two formulas are satisfied, the speed and position of the BeiDou-2 B3 navigation information source are considered normal; otherwise, go to (53);

[0039] Where V B1 , P B1 is the speed and position of BeiDou-2B1 in the launch inertial system;

[0040] (53) Determine whether |dV is satisfied B3 -dV SINS |≤ε dV 、|dP B3 -dP SINS |≤ε dP If the conditions are met, the speed and position of the BeiDou-2 B3 navigation information source are considered normal; otherwise, the speed and position of the BeiDou-2 B3 navigation information source are considered abnormal.

[0041] Where, dV B3 、dP B3 is the velocity increment and position increment of BeiDou-2B3 in the launch inertial system; dV SINS 、dP SINS is the velocity increment and position increment of the strapdown inertial group in the launching inertial system, ε dV , ε dV It is the preset speed increment threshold and position increment threshold.

[0042] Preferably, the WGS84 earth-fixed system speed and position of the three-way navigation information of GPS / GLONASS, BeiDou-2 B1 and BeiDou-2 B3 are converted to the launch inertial system to obtain the speed and position of GPS / GLONASS, BeiDou-2 B1 and BeiDou-2 B3 in the launch inertial system.

[0043] Preferably, converting the WGS84 fixed position of GPS / GLONASS, BeiDou-2B1, and BeiDou-2B3 navigation information to a transmitting inertial system comprises:

[0044] calculate:

[0045]

[0046]

[0047]

[0048]

[0049] Φ=λ0-ω e0 ·t

[0050] Where P ix , P iy , P iz are the position information of the three coordinates in the launch inertial system with navigation information source i, where i represents any one of GPS / GLONASS, BeiDou-2B1 and BeiDou-2B3; are the position information of the three coordinates of the navigation information source i in the WGS84 fixed system; A0 is the launch azimuth of the carrier rocket; λ0 and B0 are the longitude and latitude of the launch station of the carrier rocket; ω e0 is the angular velocity of the earth's rotation; t is the current satellite navigation positioning time with the launch vehicle ignition and takeoff time as the zero point; is the transformation matrix from WGS84 system to the launch inertial system; [Φ] is the intermediate transformation matrix from the WGS84 Earth-fixed system to the transmitting inertial system; Φ is the longitude deviation angle of the inertial Earth-fixed system.

[0051] Preferably, converting the WGS84 earth-fixed system velocity of GPS / GLONASS, BeiDou-2 B1, and BeiDou-2 B3 navigation information to the launch inertial system includes:

[0052]

[0053] Where V ix 、V iy 、V iz They are the velocity information of the three coordinates of the navigation information source i in the transmitting inertial system, They are the velocity information of the three coordinates of the navigation information source i in the WGS84 fixed system.

[0054] Preferably, the method for calculating the speed and position of the strapdown inertial group in the launching inertial system is: according to two consecutive strapdown inertial group navigation results before the satellite navigation positioning time, the speed and position of the strapdown inertial group in the launching inertial system at that time are calculated;

[0055]

[0056]

[0057] Where t is the current satellite navigation positioning time with the launch vehicle take-off time as the zero point; V SINS(t) , P SINS(t) The inertial system speed and position of the strapdown inertial group at the current satellite navigation positioning moment; t SINS(k) 、V SINS(k) , P SINS(k) is the inertial system speed and position obtained from the strapdown navigation solution cycle before the satellite navigation positioning time; t SINS(k-1) 、V SINS(k-1) , P SINS(k-1) It is the inertial system speed and position obtained from the two strapdown navigation solution cycles before the satellite navigation positioning time.

[0058] The advantages of the present invention compared with the prior art are:

[0059] The present invention integrates the three-channel satellite navigation information positioning results and the strapdown inertial group navigation results, selects the satellite navigation positioning information with the highest current confidence through an efficient and reliable redundant diagnosis scheme, improves the reliability of the satellite navigation system, and ensures the precise orbit entry of the carrier rocket. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0061] Figure 1 This is a flow chart of a multi-channel satellite navigation information source redundancy method applicable to a launch vehicle according to an embodiment of the present invention;

[0062] Figure 2 This is a flow chart of GPS / GLONASS positioning speed and position validity judgment according to an embodiment of the present invention;

[0063] Figure 3 This is a flow chart of determining the effectiveness of positioning speed and position of BDS B1 according to an embodiment of the present invention;

[0064] Figure 4 This is a flow chart of determining the positioning speed and position validity of BDS B3 according to an embodiment of the present invention. DETAILED DESCRIPTION

[0065] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0066] The multi-channel satellite navigation receiver sends PPS pulses and positioning information frames containing three navigation information sources, namely GPS / GLONASS, BeiDou-2 B1 and BeiDou-2 B3, to the onboard computer at a fixed period. The positioning information frame contains the flag of each navigation information source, the PDOP value and the position and velocity results under the WGS84 ground fixed system. Based on the above information, the present invention proposes a multi-channel satellite navigation information source redundancy method suitable for launch vehicles, and performs redundant navigation design for the three navigation information sources, namely GPS / GLONASS, BeiDou-2 B1 and BeiDou-2 B3. Figure 1 As shown, including:

[0067] Step 1: According to the cycle of sending navigation positioning results by the multi-channel satellite navigation receiver, determine whether the navigation information source is working normally in each cycle; where the current positioning cycle is recorded as n and the previous cycle is recorded as n-1.

[0068] Conditions for judging whether GPS / GLONASS, BeiDou-2B1 and BeiDou-2B3 are working properly: judge whether the flag of the current navigation information source is in normal state.

[0069] Flag_GNSS, Flag_B1, and Flag_B3 corresponding to the three navigation information sources of GPS / GLONASS, BeiDou-2B1, and BeiDou-2B3 are the flags of whether the data of the three signal sources are normal, and the initial values ​​are all 1. 1 means normal, and 0 means fault.

[0070] Based on the comprehensive consideration of the positioning accuracy, application maturity and reliability of the three navigation information of GPS / GLONASS, BeiDou-2B1 and BeiDou-2B3, their priority usage is determined in descending order as GPS / GLONASS, BeiDou-2B1 and BeiDou-2B3.

[0071] First, determine the Flag_GNSS of GPS / GLONASS. If Flag_GNSS is 1, go to step 2 to determine whether the GPS / GLONASS navigation information source data is valid.

[0072] If Flag_GNSS is 0, then determine Flag_B1 of BeiDou-2 B1. If Flag_B1 is 1, go to step 3 to determine whether the BeiDou-2 B1 navigation information source data is valid.

[0073] If Flag_B1 is 0, then determine Flag_B3 of BeiDou-2 B3. If Flag_B3 is 1, go to step 4 to determine whether the BeiDou-2 B3 navigation information source data is valid.

[0074] If Flag_B3 is 0, go to step 2 to determine whether the GPS / GLONASS navigation information source data is valid.

[0075] Step 2: Determine whether the GPS / GLONASS navigation information source data is valid

[0076] Collect GPS / GLONASS navigation information, and determine whether the GPS / GLONASS navigation information source data is valid under the following conditions: whether the output flag of the navigation information source is normal; whether the PDOP value of the navigation information source is less than the preset PDOP threshold value; and whether the speed and position of the navigation information source are normal. If the above three conditions are met, the navigation information source data is valid, the fault count of the navigation information source is cleared, the signal source flag Flag_GNSS is set to 1, and the process goes to step 5. Among them, the initial value of the fault value of each of the three navigation information sources is 0.

[0077] If any of the above three conditions is not met, the navigation information source fault count is increased by 1, and it is determined whether the navigation information source fault count is less than the threshold value. If it is less than the fault threshold value, the integrated navigation is not performed in the current cycle. Otherwise, Flag_GNSS is set to 0 and the process goes to step 3.

[0078] Among them, it is judged whether the speed and position of the navigation information source are normal, such as Figure 2 As shown:

[0079] (1) Collect BeiDou-2 B1 navigation information and determine whether the output flag of BeiDou-2 B1 navigation information source is normal and whether the PDOP value is less than the PDOP threshold value. If both are satisfied, determine whether |V is satisfied in the launch inertial system. GNSS -V B1 |≤ε V 、|P GNSS -P B1 |≤ε P If all the above formulas are satisfied, the speed and position of the GPS / GLONASS navigation information source are considered normal. Otherwise, go to (2).

[0080] Where V B1 , P B1is the velocity and position of BeiDou-2B1 in the launch inertial system, V GNSS ,

[0081] P GNSS is the velocity and position of GPS / GLONASS in the transmitting inertial system, ε V , ε P It is the preset speed threshold and position threshold.

[0082] (2) Collect BeiDou-2 B3 navigation information and determine whether the output flag of BeiDou-2 B3 navigation information source is normal and whether the PDOP value is less than the PDOP threshold value. If both are satisfied, determine whether |V is satisfied in the launch inertial system. GNSS -V B3 |≤ε V 、|P GNSS -P B3 |≤ε P ;

[0083] If all the above formulas are satisfied, the speed and position of the GPS / GLONASS navigation information source are considered normal. Otherwise, go to (3).

[0084] Where V B3 , P B3 is the speed and position of BeiDou-2B3 in the launch inertial system.

[0085] (3) Determine whether |dV is satisfied GNSS -dV SINS |≤ε dV 、|dP GNSS -dP SINS |≤ε dP If the conditions are met, the speed and position of the GPS / GLONASS navigation information source are considered normal. Otherwise, the speed and position of the GPS / GLONASS navigation information source are considered abnormal.

[0086] Where, dV GNSS 、dP GNSS is the velocity increment and position increment of GPS / GLONASS in the transmitting inertial system, dV SINS 、dP SINS is the velocity increment and position increment of the strapdown inertial navigation system in the transmitting inertial system, ε dV , ε dP It is the preset speed increment threshold and position increment threshold.

[0087] Step 3: Determine whether the BeiDou-2 B1 navigation information source data is valid;

[0088] Collect BeiDou-2 B1 navigation information. The conditions for judging whether the BeiDou-2 B1 navigation information source data is valid are: whether the output flag of the navigation information source is normal, whether the PDOP value is less than the set PDOP threshold value; whether the speed and position of the navigation information source are normal. If the above three conditions are met, the navigation information source data is valid, the navigation information source fault count is cleared, the signal source flag Flag_B1 is set to 1, and go to step 5.

[0089] If any of the above three conditions is not met, the navigation information source fault count is increased by 1, and it is determined whether the navigation information source fault count is less than the fault threshold value. If it is less than the threshold value, the integrated navigation is not performed in the current cycle. Otherwise, Flag_B1 is set to 0 and the process goes to step 4.

[0090] Among them, it is judged whether the speed and position of the navigation information source are normal, such as Figure 3 As shown:

[0091] (1) Collect GPS / GLONASS navigation information and determine whether the output flag of the GPS / GLONASS navigation information source is normal and whether the PDOP value is less than the PDOP threshold value. If both are satisfied, determine whether |V B1 -V GNSS |≤ε V 、|P B1 -P GNSS |≤ε P ; If all the formulas are satisfied, the speed and position of the BeiDou-2 B1 navigation information source are considered normal. Otherwise, enter

[0092] (2).

[0093] (2) Collect BeiDou-2 B3 navigation information and determine whether the output flag of BeiDou-2 B3 navigation information source is normal and whether the PDOP value is less than the PDOP threshold value. If both are satisfied, determine whether |V is satisfied in the launch inertial system. B1 -V B3 |≤ε V 、|P B1 -P B3 |≤ε P ; If all the formulas are satisfied, the speed and position of the BeiDou-2 B1 navigation information source are deemed normal.

[0094] Otherwise, go to (3).

[0095] (3) Determine whether |dV is satisfied B1 -dV SINS |≤ε dV 、|dP B1 -dP SINS |≤ε dPIf the conditions are met, the speed and position of the BeiDou-2 B1 navigation information source are considered normal. Otherwise, the speed and position of the BeiDou-2 B1 navigation information source are considered abnormal.

[0096] Where, dV B1 、dP B1 It is the velocity increment and position increment of BeiDou-2B1 in the launch inertial system.

[0097] Step 4: Determine whether the BeiDou-2 B3 navigation information source data is valid

[0098] Collect BeiDou-2 B3 navigation information. The conditions for judging whether the BeiDou-2 B3 navigation information source data is valid are: whether the output flag of the navigation information source is normal, whether the PDOP value is less than the PDOP threshold value; whether the speed and position of the navigation information source are normal. If the above three conditions are met, the navigation information source data is valid, the navigation information source fault count is cleared, the signal source flag Flag_B3 is set to 1, and go to step 5.

[0099] If any of the above three conditions is not met, the navigation information source fault count is increased by 1, and it is determined whether the navigation information source fault count is less than the fault threshold value. If it is less than the threshold value, the current cycle does not perform integrated navigation. Otherwise, Flag_B3 is set to 0, and the current cycle does not perform integrated navigation.

[0100] Among them, it is judged whether the speed and position of the navigation information source are normal, such as Figure 4 As shown:

[0101] (1) Collect GPS / GLONASS navigation information, and determine whether the output flag of the GPS / GLONASS navigation information source is normal and whether the PDOP value is less than the PDOP threshold value. If both are satisfied, determine whether |V is satisfied in the transmitting inertial system. B3 -V GNSS |≤ε V ,

[0102] |P B3 -P GNSS |≤ε P ; If all the formulas are satisfied, the speed and position of the BeiDou-2 B3 navigation information source are considered normal. Otherwise, go to (2).

[0103] (2) Collect BeiDou-2 B1 navigation information and determine whether the output flag of BeiDou-2 B1 navigation information source is normal and whether the PDOP value is less than the PDOP threshold value. If both are satisfied, determine whether |V is satisfied in the launch inertial system. B3 -V B1 |≤ε V 、|P B3 -P B1 |≤εP ; If all the formulas are satisfied, the speed and position of the BeiDou-2 B3 navigation information source are deemed normal.

[0104] Otherwise, go to (3).

[0105] (3) Determine whether |dV is satisfied B3 -dV SINS |≤ε dV 、|dP B3 -dP SINS |≤ε dP If the conditions are met, the speed and position of the BeiDou-2 B3 navigation information source are considered normal. Otherwise, the speed and position of the BeiDou-2 B3 navigation information source are considered abnormal.

[0106] Where, dV B3 、dP B3 It is the velocity increment and position increment of BeiDou-2B3 in the launch inertial system.

[0107] Step 5: Combine the navigation information of the current navigation information source with the strapdown inertial group information to perform Kalman filter combined navigation.

[0108] In this redundant method, the speed and position calculation methods of GPS / GLONASS, BeiDou-2B1, and BeiDou-2B3 in the launch inertial system are as follows:

[0109] Convert the WGS84 fixed-ground velocity and position of the three-channel navigation information of GPS / GLONASS, BeiDou-2 B1 and BeiDou-2 B3 to the launch inertial system:

[0110] V i =[V ix V iy V iz ] T i=GNSS、B1、B3

[0111] P i =[P ix P iy P iz ] T i=GNSS、B1、B3

[0112]

[0113] In the formula, It is the three-coordinate position of i navigation in the WGS84 fixed system.

[0114]

[0115]

[0116]

[0117]

[0118] Φ=λ0-ω e0 ·t

[0119] In the formula, is the speed of i navigation in the WGS84 fixed system, A0 is the launch azimuth of the current mission of the carrier rocket; λ0 and B0 are the longitude and latitude of the launch station of the carrier rocket; ω e0 is the angular velocity of the earth's rotation; t is the current satellite navigation positioning time with the launch vehicle's take-off time as the zero point. is the transformation matrix from WGS84 system to the launch inertial system; [Φ] is the intermediate transformation matrix from the WGS84 system to the transmitting inertial system; Φ is the longitude deviation angle of the inertial Earth fixed system.

[0120] The calculation methods of velocity increment and position increment of GPS / GLONASS, BeiDou-2B1, BeiDou-2B3 and strapdown inertial group in the launch inertial system are as follows:

[0121] The strapdown inertial system velocity and position at that moment are obtained by using the two consecutive strapdown inertial system navigation results before the satellite navigation positioning moment (i.e. the moment when the onboard computer receives the satellite navigation receiver positioning PPS pulse):

[0122]

[0123]

[0124] Where t is the current satellite navigation positioning time with the launch vehicle take-off time as the zero point; V SINS(t) , P SINS(t) The inertial system speed and position of the strapdown inertial group at the current satellite navigation positioning moment; t SINS(k) 、V SINS(k) , P SINS(k) is the inertial system speed and position obtained from the strapdown navigation solution cycle before the satellite navigation positioning time; t SINS(k-1) 、V SINS(k-1) , P SINS(k-1) It is the inertial system speed and position obtained from the two strapdown navigation solution cycles before the satellite navigation positioning time.

[0125] dV i =V i(n) -V i(n-1) i=GNSS、B1、B3、SINS

[0126] dP i =P i(n) -Pi(n-1) i=GNSS、B1、B3、SINS

[0127] Where, dV i 、dP i V is the velocity increment and position increment of GPS / GLONASS, BeiDou-2B1, BeiDou-2B3 and strapdown inertial system in the launch inertial system; i(n) , P i(n) V is the speed and position of GPS / GLONASS, BeiDou-2B1, BeiDou-2B3 and strapdown inertial system in the current satellite navigation positioning cycle; i(n-1) , P i(n-1) It is the velocity increment and position increment of GPS / GLONASS, BeiDou-2B1, BeiDou-2B3 and strapdown inertial group in the previous satellite navigation and positioning cycle in the launch inertial system.

[0128] The above-described embodiments are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle, characterized in that: include: The following operations are performed in each cycle when the multi-channel satellite navigation receiver sends the navigation positioning results: Step 1: According to the navigation positioning result sent by the multi-channel satellite navigation receiver, the flag bits of the GPS / GLONASS navigation information source, the BeiDou-2 B1 navigation information source, and the BeiDou-2 B3 navigation information source are obtained, and the GPS / GLONASS navigation information source, the BeiDou-2 B1 navigation information source, and the BeiDou-2 B3 navigation information source are judged in turn whether they are working normally; if the GPS / GLONASS navigation information source is working normally, proceed to step 2; if the GPS / GLONASS navigation information source cannot work normally and the BeiDou-2 B1 navigation information source is working normally, proceed to step 3; if only the BeiDou-2 B3 navigation information source can work normally, proceed to step 4; if all the above three navigation information sources cannot work normally, proceed to step 2; Step 2: Determine whether the navigation data of the GPS / GLONASS navigation information source is valid. If valid, the fault count of the navigation information source is cleared, the flag is set to normal, and then go to step 5; If invalid, the navigation information source fault count is increased by 1, and then it is determined whether the navigation information source fault count is less than the preset fault threshold value. If it is less than the preset fault threshold value, the combined navigation is not performed in the current cycle and the next cycle is waited. Otherwise, the flag is set to fault and the process goes to step 3. Step 3: Determine whether the navigation data of the BeiDou-2 B1 navigation information source is valid. If valid, the fault count of the navigation information source is cleared, the flag is set to normal, and then go to step 5; If invalid, the navigation information source fault count is increased by 1, and then it is determined whether the navigation information source fault count is less than the preset fault threshold value. If it is less than the preset fault threshold value, the combined navigation is not performed in the current cycle and the next cycle is waited for. Otherwise, the flag is set to fault and the process goes to step 4. Step 4: Determine whether the navigation data of the BeiDou-2 B3 navigation information source is valid. If valid, the fault count of the navigation information source is cleared, the flag is set to normal, and then proceed to step 5; If invalid, the navigation information source fault count is increased by 1, and then it is determined whether the navigation information source fault count is less than the preset fault threshold value. If it is less than the preset fault threshold value, the combined navigation is not performed in the current cycle and the next cycle is waited for; otherwise, the flag is set to fault, and the combined navigation is not performed in the current cycle and the next cycle is waited for; Step 5: Combine the navigation information from the navigation information source with the strapdown inertial navigation system information to perform combined navigation.

2. The multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to claim 1, characterized in that: Get the flag information of GPS / GLONASS navigation information source, BeiDou-2 B1 navigation information source, BeiDou-2 B3 navigation information source, and determine whether GPS / GLONASS navigation information source, BeiDou-2 B1 navigation information source, BeiDou-2 B3 navigation information source are working properly. Specifically: If the flag of the GPS / GLONASS navigation information source is normal, it is considered that the navigation information source is working normally; if it is faulty, it is considered that the navigation information source is not working properly; If the flag bit of the BeiDou-2 B1 navigation information source is normal, it is considered that the navigation information source is working normally; if it is faulty, it is considered that the navigation information source is not working properly; If the flag bit of the BeiDou-2 B3 navigation information source is normal, it is considered that the navigation information source is working normally; if it is faulty, it is considered that the navigation information source is working abnormally.

3. The multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to claim 1, characterized in that: To determine whether the navigation data of the GPS / GLONASS navigation information source is valid, to determine whether the navigation data of the BeiDou-2 B1 navigation information source is valid, and to determine whether the navigation data of the BeiDou-2 B3 navigation information source is valid, the determination methods for the above three are: (1) Whether the output flag of the navigation information source to be judged is normal; (2) Whether the PDOP value of the navigation information source to be determined is less than a preset PDOP threshold value; (3) Whether the speed and position of the navigation information source to be determined are normal; If (1) to (3) are all normal, the navigation data of the navigation information source to be determined is valid; otherwise, the navigation data of the navigation information source to be determined is invalid.

4. The multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to claim 3, characterized in that: Whether the speed and position of the navigation information source to be judged are normal. If the navigation information source to be judged is the GPS / GLONASS navigation information source, the judgment method is: (31) Determine whether the output flag of the BeiDou-2 B1 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V GNSS -V B1 |≤ε V 、|P GNSS -P B1 |≤ε P ; If both of the above two formulas are satisfied, the speed and position of the GPS / GLONASS navigation information source are considered normal; otherwise, go to (32); Where V B1 , P B1 is the velocity and position of BeiDou-2B1 in the launch inertial system, V GNSS , P GNSS is the velocity and position of GPS / GLONASS in the transmitting inertial system, ε V , ε P It is the preset speed threshold value and position threshold value; (32) Determine whether the output flag of the BeiDou-2 B3 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V GNSS -V B3 |≤ε V 、|P GNSS -P B3 |≤ε P ; If both of the above two formulas are satisfied, the speed and position of the GPS / GLONASS navigation information source are considered normal; otherwise, go to (33); Where V B3 , P B3 is the speed and position of BeiDou-2B3 in the launch inertial system; (33) Determine whether |dV is satisfied GNSS -dV SINS |≤ε dV 、|dP GNSS -dP SINS |≤ε dP If the conditions are met, the speed and position of the GPS / GLONASS navigation information source are considered normal; otherwise, the speed and position of the GPS / GLONASS navigation information source are considered abnormal. Where, dV SINS 、dP SINS is the velocity increment and position increment of the strapdown inertial unit in the launch inertial system, dV GNSS 、dP GNSS is the velocity increment and position increment of GPS / GLONASS in the transmitting inertial system, ε dV , ε dV It is the preset speed increment threshold and position increment threshold.

5. The multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to claim 3, characterized in that: Whether the speed and position of the navigation information source to be judged are normal. If the navigation information source to be judged is the BeiDou-2 B1 navigation information source, the judgment method is: (41) Determine whether the output flag of the GPS / GLONASS navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B1 -V GNSS |≤ε V 、|P B1 -P GNSS |≤ε P ; If both of the above two formulas are satisfied, it is determined that the speed and position of the BeiDou-2 B1 navigation information source are normal; otherwise, enter (42); Where V B1 , P B1 is the velocity and position of BeiDou-2B1 in the launch inertial system, V GNSS , P GNSS is the velocity and position of GPS / GLONASS in the transmitting inertial system, ε V , ε P It is the preset speed threshold value and position threshold value; (42) Determine whether the output flag of the BeiDou-2 B3 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B1 -V B3 |≤ε V 、|P B1 -P B3 |≤ε P ; If both of the above two formulas are satisfied, it is determined that the speed and position of the BeiDou-2 B1 navigation information source are normal; otherwise, enter (43); Where V B3 , P B3 is the speed and position of BeiDou-2B3 in the launch inertial system; (43) Determine whether |dV is satisfied B1 -dV SINS |≤ε dV 、|dP B1 -dP SINS |≤ε dP If the conditions are met, the speed and position of the BeiDou-2 B1 navigation information source are considered normal; otherwise, the speed and position of the BeiDou-2 B1 navigation information source are considered abnormal. Where, dV B1 、dP B1 is the velocity increment and position increment of BeiDou-2B1 in the launch inertial system, dV SINS 、dP SINS is the velocity increment and position increment of the strapdown inertial group in the launching inertial system, ε dV , ε dV It is the preset speed increment threshold and position increment threshold.

6. The multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to claim 3, characterized in that: Whether the speed and position of the navigation information source to be judged are normal. If the navigation information source to be judged is the Beidou-2 B3 navigation information source, the judgment method is: (51) Determine whether the output flag of the GPS / GLONASS navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B3 -V GNSS |≤ε、|P B3 -P GNSS |≤ε P ; If the above two formulas are satisfied, the speed and position of the BeiDou-2 B3 navigation information source are considered normal; otherwise, go to (52); Where V B3 , P B3 is the velocity and position of BeiDou-2B3 in the launch inertial system; V GNSS , P GNSS is the velocity and position of GPS / GLONASS in the transmitting inertial system, ε V , ε P It is the preset speed threshold value and position threshold value; (52) Determine whether the output flag of the BeiDou-2 B1 navigation information source is normal and whether the PDOP value is less than the preset PDOP threshold value; if both are satisfied, determine whether |V B3 -V B1 |≤ε V 、|P B3 -P B1 |≤ε P ; If the above two formulas are satisfied, the speed and position of the BeiDou-2 B3 navigation information source are considered normal; otherwise , enter (53); Where V B1 , P B1 is the speed and position of BeiDou-2B1 in the launch inertial system; (53) Determine whether |dV is satisfied B3 -dV SINS |≤ε dV 、|dP B3 -dP SINS |≤ε dP If the conditions are met, the speed and position of the BeiDou-2 B3 navigation information source are considered normal; otherwise , it was determined that the speed and position of the BeiDou-2 B3 navigation information source were abnormal; Where, dV B3 、dP B3 is the velocity increment and position increment of BeiDou-2B3 in the launch inertial system; dV SINS 、dP SINS is the velocity increment and position increment of the strapdown inertial group in the launching inertial system, ε dV , ε dV It is the preset speed increment threshold and position increment threshold.

7. A multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to any one of claims 4 to 6, characterized in that: The WGS84 earth-fixed system velocity and position of the three navigation information of GPS / GLONASS, BeiDou-2B1 and BeiDou-2B3 are converted to the launch inertial system, and the velocity and position of GPS / GLONASS, BeiDou-2B1 and BeiDou-2B3 in the launch inertial system are obtained.

8. The multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to claim 7, characterized in that: Convert the WGS84 fixed position of GPS / GLONASS, BeiDou-2B1, BeiDou-2B3 navigation information to the launch inertial system, including: calculate: Φ=λ0-ω e0 ·t Where P ix , P iy , P iz are the position information of the three coordinates in the launch inertial system with navigation information source i, where i represents any one of GPS / GLONASS, BeiDou-2B1 and BeiDou-2B3; are the position information of the three coordinates of the navigation information source i in the WGS84 fixed system; A0 is the launch azimuth of the carrier rocket; λ0 and B0 are the longitude and latitude of the launch station of the carrier rocket; ω e0 is the angular velocity of the earth's rotation; t is the current satellite navigation positioning time with the launch vehicle ignition and takeoff time as the zero point; is the transformation matrix from WGS84 system to the launch inertial system; [Φ] is the intermediate transformation matrix from the WGS84 Earth-fixed system to the transmitting inertial system; Φ is the longitude deviation angle of the inertial Earth-fixed system.

9. The multi-channel satellite navigation signal source redundancy method applicable to a launch vehicle according to claim 8, characterized in that: Convert the WGS84 fixed-ground velocity of GPS / GLONASS, BeiDou-2B1, and BeiDou-2B3 navigation information to the launch inertial system, including: Where V ix 、V iy 、V iz They are the velocity information of the three coordinates of the navigation information source i in the transmitting inertial system, They are the velocity information of the three coordinates of the navigation information source i in the WGS84 fixed system.

10. A multi-channel satellite navigation information source redundancy method applicable to a launch vehicle according to any one of claims 4 to 6, characterized in that: The method for calculating the speed and position of the strapdown inertial group in the launch inertial system is as follows: according to the two consecutive strapdown inertial group navigation results before the satellite navigation positioning time, the speed and position of the strapdown inertial group in the launch inertial system at that time are calculated; Where t is the current satellite navigation positioning time with the launch vehicle take-off time as the zero point; V SINS(t) , P SINS(t) The inertial system speed and position of the strapdown inertial group at the current satellite navigation positioning moment; t SINS(k) 、V SINS(k) , P SINS(k) is the inertial system speed and position obtained from the strapdown navigation solution cycle before the satellite navigation positioning time; t SINS(k-1) 、V SINS(k-1) , P SINS(k-1) It is the inertial system speed and position obtained from the two strapdown navigation solution cycles before the satellite navigation positioning time.

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